Current potency or therapeutic quality tests of cell products used in the cellular therapy area, including simple cellular feasibility tests (live or dead cells) and metabolic activity (amount of ATP), provide very little information related to therapeutic effects in front of pathologies. Some companies have developed potency tests based on the recognition of cell surface markers or through ELISA tests (Enzyme-Linked ImmunoSorbent Assay), which have demonstrated certain success in particular cases; however, because these current tests assess just one or a few biologic activities, predictive power with regard to the therapeutic effect may be considered relatively low. This is mainly due to the fact that specific biologic activity relevance could be cancelled in the event other biologic activities are low or non-existing. The results of including this type of potency test are quite variable cellular products or doses, which implies a varied therapeutic efficiency and, therefore, a poor standardization of cell therapies. The FDA understood the issues related to potency tests for cellular products and generated a guide for the sector industry in 2012, which evidences the importance of developing quick potency tests capable of assessing multiple biologic activities, and that are designed and independently validated for different types of pathologies. The evident deficiencies of current potency tests partly explain the poor success of clinical studies, and also the regulating entities', such as the FDA's reluctance regarding the use of adult stem cells in patients.
In cell therapy, the therapeutic efficacy of cells is affected by a myriad of elements that influence their final therapeutic potency, which are still not fully understood. These elements may include donor-related elements such as the genetic background, age, health conditions, habits, etc., and process-related effects such as culture conditions, level of cell expansion, cryopreservation and dose preparation. All of these elements play a role in assessing the final product, specifically at the therapeutic level. In order to maintain the quality of therapeutic products, similarly to pharmaceutical drugs, cell products need to be tested for safety, identity, purity, and potency. However, unlike pharmaceutical drugs, the therapeutic effect of cells is based on the orchestration of multiple biological activities, while for drugs are based on the known mechanism of an individual active compound.
Due to the high heterogeneity of cell productions, and the costly and time-consuming process of quality verification, a quick potency test capable to control the therapeutic quality of cellular doses for a particular treatment has become an outstanding need in the field of cellular therapy. In vitro quick tests and testing devices could accelerate and make more efficient the steps of cell donor recruitment, manufacturing control, lot release, and the testing of cellular doses before therapeutic injection into patients.